The objectives of this research project are to study the cariostatic effects of amino acids and mutation (the one which affects plaque formation) on in vitro plaque formation and cell wall biosynthesis, and to characterize the cell wall structure involved in the bacterial adhesive interaction and the binding of glycosyltransferase in the cariogenic oral Streptococcus mutans. This research work will employ more refined assay methods for studying in vitro plaque formation in order to correlate this effect with the induction of sugar nucleotide accumulation, and peptidoglycan secretion resulting from amino acid treatment. The accumulated sugar nucleotide and peptidoglycan will be characterized to provide information for the cell wall structure affected by this treatment. Amino acid incorporation into cell wall and their cross-linking in the cell wall also be studied along with other cell wall structural changes induced by amino acid treatment. Isotope-labeled sucrose will be used for the study of glycosyltransferase distribution in order to differentiate dextransucrase from levansucrase activity in amino acid treated or untreated cells. Soluble and insoluble glucan production and agglutination test will also be examined in an attempt to correlate amino acid effect on cell wall structural change affecting these parameters. S. mutans strain C67-1 and its non-cariogenic mutant strain C67-25 are also to be used for critical study of the various aspects proposed above in order to examine the correlation between cariogenicity and possible cell wall structural change resulting from mutation.